2.0 Analysis 2.1 Introduction A credible witness account and the nature of the impact damage indicate that the aircraft stalled at low altitude during the initial climb. No pre-impact mechanical discrepancies which could have resulted in a loss of control were identified during the field examination of the wreckage, and the weather conditions were suitable for the flight. The analysis will therefore focus on the operational factors which are considered to have contributed to a departure stall and subsequent loss of control. 2.2 Aircraft Control It could not be determined why the aircraft entered the steep, rapid climb and subsequent stall after take-off; however, several factors were considered. The owner/pilot had minimal recent flying experience, having flown only 10 hours in the previous 12 months. This would likely have resulted in a deterioration of his flying skills. The extent would be difficult to measure; however, it is probable that his ability to recognize the onset of a stall and to recover with a minimum loss of altitude would have been adversely affected. The detrimental effects of minimal recent flight experience may be offset by dual flight training; however, there was no evidence that the pilot had received dual training in recent years. This, coupled with the lack of a stall warning device on the aircraft, may have delayed his recognition of the stall. Knowing that the purchaser was very interested in the aircraft may have encouraged the owner/pilot to over-demonstrate the climb performance, and effect a steep, initial climb at low airspeed. The position of the adjustable stabilizer yoke indicates that the stabilizer trim was set to a landing position at the time of the accident. Although independent flight testing determined that the pilot should have been able to over-ride the trim forces easily, the aircraft would have exhibited a nose-up tendency at take-off power. Trim cable slippage may have occurred after lift-off and distracted the pilot as he attempted to retrim the aircraft; however, there was no evidence to confirm this possibility. Departure stalls must be recognized instantly and recovery initiated without delay, as the available altitude for recovery is very limited. The low altitude at which the aircraft stalled precluded an effective recovery. 3.0 Conclusions 3.1 Findings The aircraft stalled during the initial climb, at low altitude, which precluded a successful recovery. The stabilizer trim was set near the full nose-up position. There was no evidence found of any pre-occurrence airframe failure or system malfunction. The aircraft was not fitted with a stall warning device, nor was one required by existing regulation. There was no record that the PA-18 elevator installation had been accomplished in accordance with an applicable STC. The aircraft was operated with unleaded automotive fuel; however, there was no evidence that the requirements of Transport Canada document TP 10737, Use of Automotive Gasoline (Mogas) in Aviation had been complied with. The stabilizer yoke is oriented upside down in the PA-12 Parts List illustration. The aircraft was fitted with seat-belts which utilized obsolete metal-to-fabric type buckles. 3.2 Causes The aircraft stalled on departure for reasons unknown. The low altitude at which the stall occurred precluded a successful recovery. 4.0 Safety Action 4.1 Action Taken 4.1.1 Parts List Illustration The Parts List illustration for the PA-12, and also those for the Piper J-3 and PA-11 aircraft, incorrectly depicts the orientation of the horizontal stabilizer yoke assembly. An Aviation Safety Information Letter apprised Transport Canada of this anomaly.